The present invention refers to a method and apparatus of cleaning fibrous material which is fed in the form of a sliver to an opening roller and is opened into individual fibers and, subsequently, fed to an open-end spinning device.
In known opener units of preparatory machines in spinning mills, the coarse impurities such as leaf, stalk and seed-kernal residues are largely removed and eliminated by beating action upon the cotton flock. But in that case, there is effected not only elimination but also partial smashing of these bits, whence arise particles of 300.mu. and smaller, which cling to the fibers again as microscopic dust. Hence, the fibers remain burdened with considerable amounts of microscopic dust, the greater proportion of which amounts to 150.mu. or is still finer (Melliand Textilberichte August 1976, pages 609 to 613).
With open-end spinning devices, the practice is known of loosening the sliver as far as single fibers, and in this form, leading it past a trash separator opening which exhibits a separator edge (West German O/S No. 1 914 115). For avoiding loss of fibers, an airstream directed against the direction of flight of the dirty matter is introduced into the fiber-air stream led to the spinning rotor. Dirty matter which is just as light or even lighter than fibers is held back by this infed flow of air just like the fibers and arrives with the fibers in the spinning rotor. Here the fine dust is deposited on the rotor wall and in the collector groove and interfers with the spinning operation. The shape of the groove is continually altered and the spinning process disturbed, whereby yarn breakages arise.